And with finally finishing Armored Core 2 Another Age this past weekend, I am now moving on to Armored Core 3 to unlock the OP-Intensify upgrades to make playing through Silent Line easier as I have tried it without OP-Intensify and quit after awhile because of how much trouble I was having. I have already beaten Armored Core 3 last summer along with unlocking some of the secret parts like the Karasawa, Moonlight blade, CROW stealth extensions, Mirror shield, etc. (never going to attempt getting the secret part for dodging all the missiles from MT's again, after like 73628764 attempts I gave up). I know theres a list of challenges in AC3 that you have to complete with OP-Intensify equipped in order to unlock the abilities for it although I have been having trouble with some of them. I am going by a list I found for it on the GameFAQS website, I managed to do the first challenge in this list and I'm currently working on the second one where you have to fight and win against Ace in the Arena with OP-Intensify equipped. I'm almost there but have to defeat Royal Mist's Kaiser AC and BB's Tyrant AC before facing Ace. I'm having trouble with Kaiser because his AC is so heavily armored it seems like even the most powerful weapons I have barely do anything to him. Hell, I even pulled out the linear cannon with close to 6000 attack blasting him at point blank range when he tries to get in my face going through all of the ammo for it into him and he still doesn't go down. I have tried using the Karasawa and that doesn't help much either, I know I have great defense as I'm also using a heavily armored AC with the Mirror shield and anti-missile extensions but I'm having trouble finding powerful enough offensive weapons to take him down with. Anyone have any advice on any other powerful weapons I should try using against him? Any advice for any of the other challenges on this list? Is there a secret part of weapon that may help that I missed out on in my initial play-through?

Well, first off, for dodging the missiles, you have to use the crow extension part, with the ECM inside part, and just use in about every 5 seconds. I had to look up a guide on Gamefaqs before I was able to unlock the part.

Ok I was wondering about the dodging missiles challenge, I had heard somewhere before that you need the CROW stealth extensions to do it but wasn't sure how to use it as with most extensions you just activate it with pressing the left analog stick and it just works for the rest of the fight in the older AC games. I know about the arena opponents and missions you have to use it on, I looked through the thread you posted though and didn't see much, if any, advice on doing those challenges such as strategies, tactics or gear suggestions for beating some of the top arena opponents which are necessary for beating them along with some of the missions you have to use it on since when you use it at first as you know it takes up all the space for optional parts which holds back the AC more than improves it. I think the only one I know I can handle that is a requirement is using the OP-Intensify on the mission to destroy the massive MT which I did with the linear cannon although not so sure on the other missions required for it. I'm wondering if I should be trying to play through the required missions with it first then go through the Arena so that the part doesn't hold my AC back so much at first.

An update to this thread, I actually managed to unlock every OP-Intensify ability except firing cannons without kneeling which is earned by destroying both parts of the massive mt in the destroy massive mt mission. I have been at it for hours and can't figure out how I'm supposed to do this, even with a consort it doesn't matter because the massive mt keeps coming after me and killing me so if I turn around to fire at the other part with the grenade launchers a swarm of missiles kills me yet when I pay full attention to the massive mt if I don't kill him fast enough a volley of grenades kill me but if I kill him without killing the other part with the grenade launcher before killing him then I get nothing (I already unlocked the ability for just killing him with OP-Intensify enabled). I'm really confused and frustrated as to how I'm supposed to do this, really don't understand why challenges so close to being impossible like this are always thrown in armored core games all the time...

Another update, I finally did it and unlocked all of the OP-Intensify abilities. Turns out the answer was staring me in the face like you were trying to tell me Siphon, used the CROW stealth extensions to stop the massive mt from using his missiles on me while I focused on taking out the other section then I finished him off with the Karasawa. Only thing left is to use your suggestion on the mission with dodging missiles to get that secret part then I believe I'll basically be done with Armored Core 3 and can move onto Silent Line.